I’d think a Marine Band or Blues Harp would work to get the Dylan sound.
There was a time when those were THE harp to play.
To get them to sound right they either require a breaking in period or you can run water/booze through them to loosen up the reeds.
I met harp player once who did neither. He just bought a new one before every gig and blew the heck out of it and tossed it at the end of the night.
There is a drawback to the liquid method. First, the wood swells. You haven’t lived until you’ve had your lips abused by swollen harp wood. Additionally, this swelling will eventually cause the metal plates to separate slightly from the wood. This is good for yanking mustache hairs.
Second, the reeds will be stiffer then they started and you will always have to drown the harp to get it to sound nice.
The primary harp used by Howard Levy is the Hohner Golden Melody. He had perfected the art of the blow-bend which gives him a chromatic scale on a diatonic harp. He claims the Golden Melody has more supple reeds and makes it easier to bend blow notes.
I use the Lee Osker harp. They are responsive right off the shelf and the reeds are strong so there’s less likelyhood of the G and low F harps to blow reeds. They usually cost around $35.00 apiece. You can get them from Elderly’s Instruments for $25.00
Because the harmonica is a diatonic instrument, (except the chromatics which I don’t care for), you can use the same rules of thumb as you do with whistles regarding playing in certain keys. You can play most of the same modes though I only use the Major and the Dorian and whatever the 5th mode is (Mixolydian?).
For blues/bluegrass I usually play in cross-harp or 2nd position. It’s the most popular for blues.
The key you play in 2nd position is the 5th of the key of the harp. Thus, a C harp would play G, the A harp, D, G harp, D.
A lot of harp players will tweak their harps so it has even more in common with the whistle.
Nowdays there’s alternate tuned harps. I just bought a Lee Oskar Natural Minor harp (Em). I haven’t spent much time with it yet so I don’t know how I’ll use it. Being from the old school I still prefer the standard tuning.